Gas lift valves



J. D. WATERS GAS LIFT VALVES Sept. 6, 1966 2 Sheets-Sheet 1 Filed June s, 1962 6 INVENTOR. James D. Waters mi@ Fig.|

sept. 6, 1966 Filed June 6,v 1962 J. DfwATERs GA S LIFT VALVES 2 Sheets-Sheet 2 James D. Wctzs. www? United States Patent O 3,270,765 GAS LIFT VALVES James D. Waters, Houma, La., assignor to Otis Engineering Corporation, Dallas, Tex., a corporation of Delaware Filed June 8, 1962, Ser. No. 201,022 8 Claims. (Cl. 137-155) This invention relates to air or gas lift valves for use in oil wells and the like for controlling admission of gas or air to a column of fluid into the well to lift the column and aid in flowing the Huid from the well.

In conventional gas lift systems, the well equipment usually includes a string of relatively small pipe called the tubing which is inserted inside a larger diameter pipe called the casing The liquids produced by the well may flow to the surface through the tubing, in which case gas or air may be introduced under controlled pressures and volumes into the annular space or annulus between the tubing and the casing and injected through suitable gas lift valves into the tubing to aid in lifting the column of oil inside the tubing to the surface. Alternatively, the liquids produced by the well may flow to the surface through the annulus in which case the gas or air used in aiding in lifting the oil to the surface is introduced into the tubing and injected through suitable gas lift valves into the cylindrical column of liquid in the annulus. It is desirable that such gas lift valves be of such structure that the bore of the tubing is not decreased at the locations where the gas lift valves are connected to the tubing and that additionally the external diameter of such valves be as small as possible in order to permit the passage of well tools through such gas lift valves and also to permit passage of fluid through the annulus during wash over operations of the well and the like.

Accordingly, an object of this invention is to provide a new and improved gas lift valve, connectable in a string of tubing to form a section thereof, having a central longitudinal passage or bore of a diameter not smaller than the bore of the tubing.

Another object is to provide a gas lift valve having a -relatively small outside diameter.

Another object is to provide a gas lift valve having means for ensuring smooth relatively slow movement of the operative components of the valve during its operation.

Still another object is to provide a gas lift valve of concentric construction connectable in a string of tubing to form a section thereof having an internal longitudinal passage or bore which is not smaller than the drift diameter of the tubing and an annular flow passage disposed concentrically about the longitudinal passage, the valve having ports communicating the flow passage with the interior of the tubing and the exterior thereof, and also having valve means responsive either to the pressure within the tubing or the pressure exteriorly of the tubing for controlling flow of fluid through the passage either fromthe tubing to the exterior of the tubing or from the exterior of the tubing into `the tubing.

' Still another object is to provide a gas lift valve wherein the valve means controlling flow of gas through the passage is biased towards closed position by a charge of compressed gas acting on a resilient member, such as a bellows, with the valve being moved to its open position by either the pressure within the tubing or the pressure within the annulus between the tubing and the casing of the well.

A further object is to provide a gas lift valve having means for protecting the resilient means of the valve against overstressing in the event the pressure to which the resilient means is exposed rises to excessive values.

A still further object is to provide a gas lift valve wherein the operative components of the gas lift valve are not exposed either to the interior or the exterior of the tubing in order to prevent their damage by well tools, high pressures, ow cutting, erosion or other forces.

A still further object is to provide a gas lift valve which minimizes leakage of iluids through the valve when the valve is in closed position.

Another object of the invention is to provide a gas lift valve having a mandrel and a sle'eve on the mandrel forming a passage between ports of the mandrel and the sleeve, a valve member for closing the passage between the ports of the mandrel and the sleeve which is biased towards closed position by a charge of compressed gas acting 0n a concentric bellows disposed about the mandrel wherein the effective area of the bellows exposed to the pressure of the charge of gas is sufficiently great to assure tight closing of the valve member.

Still another object is to provide a gas lift valve wherein the charge of gas is confined in a chamber having a port communicating with the bellows and wherein the valve member has a valve port closure which closes such port when the valve member is moved to its fully open position to prevent further flow of incompressible liquid filling the bellows into the gas chamber whereby further stressing of the bellows is prevented by such incompressible liquid when the valve is in its fully open position.

Still another object is to provide a new and improved gas lift valve having a bellows formed of two concentric sections and having means interposed between the inner and outer bellows sections for preventing contact between the two sections and for holding the bellows in proper position.

A further object is to provide a gas lift valve which opens when a pressure to which the valve is exposed reaches a predetermined value regardless of the temperature conditions in the well.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying draw- FIGURE 2 is a sectional view taken on line 2 2 of FIGURE 1;

FIGURE 3 is a perspective view of a valve member for controlling flow of lifting gas through the passage of 4the gas lift valve from the annulus into the tubing;

FIGURE 4 is a fragmentary view, partly in section and partly in elevation, of a modilied form of the gas lift valve embodying the invention wherein the valve is responsive to the pressure within the annulus for controlling flow of gas from the annulus into the tubing;

FIGURE 5 is a fragmentary sectional view taken on line 5 5 of FIGURE 4;

FIGURE 6 is a fragmentary view, partly in section and partly in elevation, of another modied form of the valve for controlling iiow of fluid ifrom the tubing into the annulus wherein the valve is responsive to the pressure of the annulus;

FIGURE 7 is a fragmentary view, partly in section and partly in elevation, of another modied form of the valve for controlling flow of lifting gas from the tubing to the annulus wherein the valve is responsive to the pressure of the fluid within the tubing;

FIGURE 8 is a fragmentary View, partly in section and Patented Sept.` 6, l1966- partly in elevation, of a modified form of the valve illustrated in FIGURE 1 `wherein the outer and inner bellows sections are longitudinally displaced to minimize the outside diameter of the valve; and,

FIGURE 9 is a view, partly in eleva-tion and partly in section, of another modified form of the valve illustrated in FIGURE l, wherein the valve member is biased toward closed position by a spring.

Referring now particularly .to FIGURES 1 through 3 of the drawing the gas lift valve 20 is shown connected between the sections 21 and 22 of a string of tubing T which extends through the casing 24 of a well. The valve includes a mandrel 25, the diameter of whose bore is substantially as great as that of the sections of the string of tubing T. The mandrel is connected to the tubing sections 21 and 22 by the usual couplings or collars 27.

A sleeve is mounted on the mandrel and has an internal annular `liange 31 whose lower end abuts a nut 33 threaded on the lower end of the mandrel above the coupling 27. The nut limits downward movement of the sleeve on the mandrel. The internal annular ilange of the sleeve is provided with an internal recess in which is disposed an O-ring 34 or other suitable sealing means for sealing between the flange and the mandrel. Up- Ward movement of the sleeve on the mandrel is prevented by the closure ring 35 rigidly secured to the mandrel in any suitable manner, as by a weld 36 which also provides a uid tight seal between the closure ring and the mandrel. The closure ring has a reduced lower portion 38 which telescopes into the upper end of the sleeve 30 and provides a downwardly facing shoulder 39 which engages the upper end of the sleeve. The reduced lower portion of the ring has an external annular recess in which is disposed an O-ring 41 or other suitable sealing means which seals between the closure -ring and the sleeve 'below the stop shoulder 39 of the closure ring. The bore of the closure ring is enlarged as at 43 to provide communication between the lateral iiller port 44 of the closure ring and the annular pressure chamber 45, A plug 46 threaded in the filler port engages a gasket 47 to close `the filler port.

It will now be apparent that the sleeve, the closure ring and the mandrel provide an annular space or chamber about the mandrel which is divided into the gas pressure chamber 45 and `a bellows chamber 48. A ring or partition 50 rigidly secured to the mandrel by any suitable means, such as silver solder, provides a iluid tight seal between the mandrel and the partition. The partition has 'an external annular recess in which is disposed an O-ring 52, or other suitable sealing means for sealing between the partition and `the sleeve.

The bellows chamber opens downwardly to a flow passage 55 formed by the sleeve and the mandrel which communicates with one or more ports 56 of the mandrel and with the ports 57 of the sleeve. A port ring 59 in the ow passage is rigidly secured to the mandrel by any suitable means, such as silver soldering, which provides a fluid tight seal between the port ring and the mandrel. The port ring has an external annular recess in which is -disposed an O-ring 60 or other suitable sealing means which seals between the port ring ond the sleeve, so that ow of uid through the ow passage between the ports 56 and 57 of the mandrel and the sleeve, respectively, may take place only .through the ports 61 of the port ring.

In order to prevent ow of uid from the tubing to the annulus between Ithe tubing and the casing, a resilient `tubular check valve 63 is mounted in the flow passage 55 and has a base portion provided with an internal annular ilange 64 which is receivable in an external annular recess 65 of the mandrel `which holds the check valve against upward movement in the flow passage. Downward movement of the check valve is of course prevented by the engagement of its lower end with an upwardly facing annular shoulder 66 of the internal flange 31 of the sleeve. The check valve has an upper lip portion 67 which is moved into engagement with the internal surfaces of the sleeve 30 to close the ports 57 when the pressure within the tubing exceeds lthe pressure within the annulus.

The circumferentially spaced ports 61 of the port ring are closable by the similarly spaced valve tips 70, which engage the seats 71 of the port ring, disposed on the lower ends of the dependent ngers 72 of the cylindrical valve means or member 73 disposed in the annular bellows chamber 48 between the sleeve and the mandrel above the port 56 of the mandrel. The Valve member has internal and external annular flanges 75 and 76 which are engageable with the mandrel and the sleeve to maintain the valve member properly positioned and spaced between the mandrel and the sleeve.

The valve member also has a longitudinally extending giuide rod 77 slidably received in a passage 78 of the partition 50 which communicates with the pressure chamber 45. The guide rod is somewhat smaller in diameter than the passage 78 so that fluid may flow through the passage past the guide rod. The lower end portion of the guide rod provides a beveled seat surface 79 which is engageable with the valve seat 82 of the partition when the valve member 73 is moved to its upper position to clos-e the passage 78 against flow 'of fluids therethrough and past the guide rod.

The partition 50 has a dependent reduced annular portion providing an inner annular surface to which is secured the upper end portion 84 of the inner bellows section 85 by any suitable means, such as silver solder, which provides a iluid tight seal therebetween and an outer annular surface to which the upper end portion 87 of the outer bellows section 88 is similarly secured. The lower end portions 89 and 90 of the inner and outer bellows sections, respectively, are similarly secured to the valve member 73 immediately Vabove the inner and outer `guide flanges 75 and 76, respectively, so that the interior of the annular bellows formed by the two sections and the valve member 73 is in communication with the pressure chamber 45 whenever the valve member 73 is in a lower position with the valve seat 79 of the guide rod 77 spaced from the seat 82 of the port ring. The pressure yof the gas in the pressure chamber 45 acts on the bellows sections to tend to move the valve member downwardly and cause the beveled surfaces of the valve tips 70 to engage the seats 71 of the port ring and thus close the ports 61. The bellows formed by the two sections is of course also exposed to the pressure from the interior of the tubing when the valve member is in its Ilower position with the ports 61 closed since the ports 56 of the mandrel communicate at all times with the bellows chamber 48 so that the pressure from the interior of the mandrel tends to move the valve member upwardly towards its upper position.

The effective area of the bellows exposed to the pressure of the compressed gas in the pressure chamber 45 tending to move the valve member to its lower port 61 in closing position is the difference between the effective areas of the outer and inner bellows sections and is of course much greater than the total areas of the valve tips exposed to the pressure in the flow passage 55 below the port ring 60 so that the force of the compressed gas tending to hold the valve member in its lower position when the valve member is in its lower port closing position is much greater than the force of the pressure from the annulus acting on the areas Yof the valve tips exposed to such pressure through the ports 61. For example, if the ports 61 Iof the port ring 59 are each three-sixteenths inch in diameter, the total cross sectional area of the three ports is .0828 square inch. If the effective area of the outer bellows section 88 is 6.77 square inches and the eiective area of the inner bellows section is 4.66 square inches, then the effective area of the bellows exposed to the pressure of the compressed gas is 2.11 square inches. It will thus be apparent that the force exerted by the compressed gas trom the chamber 44 acting on the bellows will greatly exceed the force of the annulus pressure acting on the valve tips and tending to move the valve to its upper position so that when the tubing pressure is lower and the valve member is in its lower closed position, the valve tips are held against the seats 71 with lrelatively great force and leaking therebetween is prevented or greatly minimized.

An incompressible liquid ti-lls the interior of the bellows between the two bellows sections and lls the passage 78. When the valve member 73 is moved towards its upper position, the restricted eorice of the passage 78, due to the presence of the guide rod 77 therein, slows down or damps the movement of the valve member by slowing down the flow of the liquid through the passage 78 into the pressure chamber 45. Downward movement of the valve member toward its lower closed position is similarly slowed down due to the restriction of the flow of the liquid from the pressure chamber to the bellows. The gas lift valve is thus caused to operate smoothly without abrupt and sudden movements, and the operational life of the gas lift valve is prolonged.

When the valve member is lifted to its uppermost position wherein the valve seat surface '79 engages the seat 84 'of the partition ring 50, the passage 78 is closed and the liquid in the bellows can no longer escape through the passage 78. The incompressible liquid thus trapped within the bellows now prevents damage or crushing of the bellows sections in the event that the pressure within the bellows chamber exteriorly of the bellows section rises to high values.

It will also be apparent that since the cylindrical valve guide is disposed between the two bellows sections, the corrugations Iof the two bellows sections cannot touch one another and thus do not tend to `abrade or damage each other during the movement of the valve member.

In use, the bellows is first filled with the incompressible liquid and the pressure chamber 45 of the gas lift valve is then lled with a gas under predetermined pressure through the filler port 44. The til-ler port is then closed by screwing the plug 46 inwardly against the gasket 47. Any other suitable means may be employed in place of the plug 46 and the gasket 47, if desired. For example, a valve may be screwed in the thread portion of the ller port which permits flow into the chamber but prevents reverse flow from the chamber. Such valve may be similar to the well known valves used for the introduction of air into pneumatic tires.

The mandrel 2S of the gas lift valve is connected between adjacent ends of adjacent sections, such as the sections 21 and 22, of the tubing string which is then lowered into the well casing. The open lower end of the tubing string is in communication with the bore of the well casing and a producing formation and a suitable packer seals the annulus between the tubing and the well casing below the gas lift valve. The pressure of the compressed gas in the pressure chamber 45 now holds the valve member in its lowermost position wherein its valve tips 70 close the ports 61 of the port ring 59 and thus holds the flow passage 55 closed to flow between the ports 56 and 57 of the mandrel and the sleeve, respectively. Lifting gas is then injected into the annulus between the tubing and the well casing through suitable control means. The well liquids flow upwardly in the tubing and form a column above the ports 56 of the mandrel. When the height of the column of well liquids above the ports 56 attains a predetermined height, the hydrostatic pressure within the tubing now communicated to the exterior of the bellows through the ports 56 causes upward movement of the valve member 73 against the resistance of the compressed gas in the pressure chamber 45. The Valve member of course moves upwardly slowly and smoothly due to the restricted orifice of the passage 78 of the partition 50 which permits the incompressible liquid to ow at a slow controlled rate into the pressure chamber. The lifting gas then tlows through the ports 57 of the sleeve inwardly into the ow passage 55 past the check valve 63 which flexes inwardly and thence through the passage 61 of the port ring and the ports 56 of the mandrel and into the interior of the tubing. The ports 61 are much smaller in area than the ports 56 and 57 of the mandrel and of the sleeve, respectively, and restrict the ow of lifting gas therethrough creating a drop in pressure thereacross. As a result of this rectriction and drop in pressure, the pressure immediately downstream of th ports 61 is always substantially equal to the pressure in the tubing and therefore the valve member 73 will be maintained in its upper open position until the flow of lifting gas into the tubing lifts the column or slug of oil upwardly in the tubing and discharges it at the surface. At this time, the pressure in the tubing decreases and when it drops below the predetermined Value, the force exerted by the gas under pressure in the chamber 45 is again effective to move the valve member downwardly towards its closed position. Such downward movement of the valve member towards its closed position is again slowed down due to the flow of the incompressible liquid through the restricted passage 78 from the pressure chamber into the bellows. When the valve member is again in its closed position, the pressure within the tubing decreases as -the column or slug of well liquids is expelled from the upper end of the tubing and the well liquids again rise upwardly in the well tubing, the valve member remaining in its closed position until the well liquids again rise to a height above the ports 56 to produce a hydrostatic pressure suiciently great to again move the valve member to its open position against the force exerted by the compressed gas in the pressure chamber 45.

As is well known in the art, a plurality of the gas lift valves may be connected in the string of tubing at longitudinally spaced locations.

It will now be seen tha-t a new and improved gas lift valve has been illustrated and described having a tubular mandrel lor member, connectible in a string of tubing to form a section thereof, whose bore is not smaller in diameter than the drift diameter of the tubing.

It will further be seen that the valve includes means, `such as the sleeve 30 and the closure ring 35, which provide a flow passage 55 between the ports 56 of the mandrel which open into the interior of the mandrel and the ports 57 of the sleeve which open to the ex-terior of the sleeve and therefore to the exterior of the tubing.

It will further be seen that a valve means which may include the por-t ring 59 and the valve member 72, is provided for controlling the llow of fluid through the flow passage 55 from the exterior of the valve through the ports 57 of the sleeve and to the interior of the tubing through the ports 56 of the mandrel.

It will further be seen that the valve means are biased toward closed position by a charge of compressed gas in a chamber 45 formed by the sleeve 30, the closure ring 35, the mandrel and the partition 50, the force exerted by the compressed gas acting on the valve means by means of a bellows connected to the valve member 73.

It will further be seen that the bellows is formed of corrugated cylindrical inner and outer bellows sections and S8 whose lower ends are secured to the valve member 73 and whose upper ends are secured to the partition 50 with the cylindrical upper portion of the valve member extending between such sections -to prevent contact therebetween, the bellows sections and the valve member being concentric with respect to the mandrel.

It will further be seen that the bellows formed by the two sections is lilled with `a noncompressible liquid and that the partition 50 and the valve member 73 are provided with means for closing the passage 78 through Ithe partition which affords communication between the pressure chamber and the interior of the bellows whereby crushing or distortion of the bellows is prevented by the noncompressible liquid trapped in the bellows when the passage is closed by the engagement of the seat 79 of the guide rod 77 with the seat 82 of the partition.

It will further be seen that the restricted orifice of the passage 78 slows down the ow of the liquid into and out of the pressure chamber 45 thus slowing down opening and closing movements of the valve member and prolonging the life of the operative par-ts of the valve.

Lt will further be noted that the operative components of the gas lift valve by their location within the chambers tab-ove the ports 56 are not exposed to either the tubing or the casing bores and therefore canot be damaged by the well tools which are moved through such bores, or by high Ipressures, erosion or flow cutting.

It will lfurther be seen that the provision of the concentric bellows in the chamber between the sleeve and the mandrel permits the mandrel to have an internal diameter which may be no smaller than the internal diameter of the tubing and also minimizes the external diameter of the gas lift valve.

It will further be seen that by the use of the concentric bellows the effective area of the bellows exposed to the pressure of the compressed gas is many times greater than fthe effective tarea of the valve tips 70 exposed to the pressure of the lifting gas in the annull-us so that the leakage of lifting gas into the tubing is prevented or minimized as long as the hydrostatic pressure in the tubing above the ports 56 of the mandrel does not exlceed .the predetermined value at which lthe gas lift valve opens to |permit -flow of lifting .gas into the tubing.

The gas lift valve 100 is similar to the gas lift valve and accordingly elements of the valve 100y have been provided with the :same reference numerals to which the suffix a has been added, as corresponding elements of the valve 20.

The ponts 57a of Ithe sleeve 30a are disposed above the port ring 59a so that fthe bellows chamber 48a of the gas lift valve 100 communicates with the annulus between the tubing and the well casing instead of with the bore of the mandrel as is the case in the valve 20 so that the valve member 76a will be moved to its upper position opening the ports 61a when the pressure within the annulus attains a predetermined value. The ports 56a of the mandrel a :are disposed below the ports 57a and the check valve 63a is disposed between .these ports in the flow passage 55a. The check valve 63a is held in position in the passage 55a by an annular retainer 102 which is secured to the mandrel by means of the retainer wire 103 which is disposed in aligned external and internal annular Irecesses of the mandrel and of the retainer, respectively. The retainer 102 has an enlarged bore 105 fin which the upper cylindrical portion of the check valve is disposed and an outwardly 4and downwardly extending support surface 106 against which abuts the lower lip portion 107 of the check valve. The lip portion is `adapted to engage the yinternal surfaces of the sleeve a below the retainer 102 to prevent upward 'flow of fluid in the flow passage 55a through ,the circumferentially spaced longitudinal slots 108 of the retainer. The check valve has an internal annular flange 110 received in .a suitable external `annular recess of the mandrel a and held against displacement from the internal recess by the retainer rings 113 disposed on opposite sides of the O-ri-ng 114 or other suitable sealing means which seals between the 'mandrel and the check valve.

I=t will now be seen that the gas lift valve 100, like the valve 20, controls flow of lifting gas from the annulus into the bore of the string of tubing to aid in lifting well liquids to the surface but that the valve 100 will open Whenever the pressure of the lifting gas within the annulus exceeds `a predetermined value regardless of the height of the column of well liquids within the bore of the string of tubing and that the check valve 63a prevents ow of fluids from the bore of the string of tubing to the annulus.

The valves 150 illustrated in FIGURE 6 controls the How of uids from the bore of the string of tubi-ng to the annulus between the string of tubing and the well casing and :is similar in structure to the valve 20 and the valve 100. The elements of the valve 150 are provided with the same reference numerals to which the suix b has been added, as the lcorresponding, elements of the valves 20 and 100. lt will be noted that the valve 150 -s similar to valve differing therefrom in that the check valve 63b is disposed to prevent ow from the annulus through fthe flow passage SS-b and into the string of tubing through the ports 56b of the mandrel 25b. The youtwardly believed support surface 10617 of the retainer 102b faces upwardly to support and retain the lip 107b of the check valve 63b which Iseals against the inner surfaces of the sleeve 30b yto prevent downward flow of fluids from. the annulus through the flow passage 55b to the ports 5619. It will therefore be apparent that the valve may be employed in a lwell wherein the well liquids flow upwardly through the annulus between the `string of tubing and the well casing and Ithat the lifting gas for aiding in 4lifting the annular column of well liquids in the annulus flows through the bore of the tubing and thence through the flow passage 55b of the gas lift valve into the annulus whenever the column of liquids above fthe :ports 57b of 'the sleeve 30h attains such a height that the hydrostatic pressure of the `well liquids exceeds a predetermined value sufficiently great to overcome the force exerted on the valve member 73h by the change iof compressed gas lacting on the bellows ysections 85h and 88h and that the valve will close Whenever the pressure in the annulus decreases below such predetermined value as the column or slug of liquids is expelled from the annulus 4at the surface.

The valve 200 illustrated in FIGURE 7 which controls the ow of :lifting gas from the bore of the string of tubing into the Iannulus whenever the pressure of the lifting gas within the tubing exceeds a predetermined value is also similar in structure to the valves 20 and 100y and accordingly elements of the valve 200 have been provided with the same reference numerals, to which the suflx c has been added, as corresponding elements of the valves 20 and 100. yIt will be lapparent that the valve 200 is identical in structure to the valve 100 except that the ports 56e open to the bellows chamber 48C so that the valve member 73a will move to open the ports 61C Whenever the pressure of the gas Within the bore of the mandrel 25C exceeds a predetermined value and thus will permit lthe flow of the lifting gas downwardly through the flow passage 55C 'and past the 'check valve 63C to the ports 57C of the mandrel 30C to aid in lifting to the surface the annular column of well fluids in the annulus between the tubing string and the casing.

It Will now be seen that by the connection of an appropriate valve 20, 100, 150 or 200 in a string of tubing, lifting gas may be introduced into -th-e well through the annulus between the string of tubing and the well casing to aid in lifting the well liquids to the surface through the tubing string or that it may be introduced through the string of tubing and into the annulus to aid in lifting a column of well liquids through the annulus to the surface. It will also be seen that in either case 4the gas lift valve may be made responsive either to the hydrostatic pressure of the column of liquid to be lifted to the surface or to the pressure of the lifting gas at the gas lift valve whether it is injected from the annulus into the tubing or from the tubing into the annulus.

The gas lift valve 250` illustrated in FIGURE 8 is similar to the valve 20 and the elements thereof have been provided with the same reference numerals, to which the suffix d has been added, as the corresponding elements of the valve 20. The valve member 73d of the valve 250 has an upper cylindrical section 251 and a lower cylindrical section 252 of smaller diameter than the upper section which are connected by the integral intermediate .annular portion 253. The lower end portion of the inner bellows section 85d is connected as at 254 by silver soldering, or the like, to the upper valve member section 251 and its upper end portion is similarly secured to the dependent annular extension 253 of the annular partitioh 50d. The partition 50d of course may be secured to the mandrel 25d by silver soldering, as at 255'. The inner bellows section 85d is therefore disposed between the upper valve member section 251 and the mandrel 25d. The guide rod 77d of the valve member extends int-o the passage 78d of the partition 50d.

The annular valve tip section 2:56 of the valve member 73d, which is provided with the lingers 72d and the valve tips 70d, telescopes into the lower end of the lower section 252 and is secured thereto in any suitable manner, as by silver soldering. The lower end portion of the outer bellows section `88a? is secured to the annular valve tip section, as at 257, by silver soldering or the like. The outer Ibellows section is of course telescoped over the lower valve member section 252 before the annular valve tip section 256 is secured to the lower end of the valve member section. The upper end portion of the outer bellows section is secured to the inner surfaces of the sleeve 30d below the intermediate section 253 of the valve member, as at 258, after the assembly has been slid into the sleeve 30d. The soldering may be accomplished by the localized application of heat to the solder contained in an internal groove 259 of the sleeve 30d, by any suitable means as by the well known induction heating devices.

It will now be seen that the valve -250 may be made of very small outside diameter due to the provision of the v-alve member 73d having upper and lower sections of different diameters so that the two bellows sections may be longitudinally displaced relative to one another. The inner and outer bellows sections open upwardly to the passage 78d, so that the force exerted by the compressed gas within the pressure chamber 45d biases the valve member downwardly to cause the valve tips 70d to move towards seating engagement with the valve seats 71d. The pressure from the bore of the mandrel 25d acts on the outside surfaces of the two bellows sections and thus tends to move the valve member 73d towards its upper open position. It will thus be apparent that the bellows section and the valve member 73d will function in the same manner as the bellows section and valve member of the valve 20, illustrated in FIGURES l through 3 but that the outside diameter Vof the gas lift valve 2'50 may be made smaller since the outer bellows section now is not in horizontal alignment with the inner bellows section.

The valve `300 illustrated in FIGURE 9 is similar to valve illustrated in FIGURE l and the elements of the valve 300 have accordingly been provided with the same reference numerals, to which the suix e has been added, as the corresponding elements of the valve 20. The valve member 73e of the valve 300 is cylindrical in form and has an upper enlarged annular portion I30l1. The upper end portions of the inner and outer bellows sections 85e and 88e are secured in liuid tight relationship to the valve member immediately below the upper enlarged por-tion 301, as at 303 and 304, respectively, by any suitable means, such as silver solder. The valve member 73e also has the valve tips 70e on the lower ends of the dependent nger 72e of the valve member. The valve tips 70e of course yare engageable with the seats 71e of the port ring 59e. The lower end portions of the inner and outer bellows sections 85e and 88e are rigidly secured, as at `30"] and 30'8, respectively, to the mandrel e and the sleeve 30e, so that the lower ends of the bellows sections may be soldered to the mandrel and to the sleeve by using apparatus for localized heating, such as induction heating apparatus.

The closure ring 36e is held against upward displacement on the mandrel 25e by a lock nut '310' threaded on the upper end of the mandrel below the usual tubing collar or coupling 27. The closure ring is provided with an internal annular recess in which is disposed an O-ring 316 which seals between the mandrel and the closure ring.

The valve member 73e is biased downwardly towards the closed position illustrated in FIGURE 9 by the spring 312 whose upper end bears against the lower annular surface 3'13 of the closure ring 35e and whose lower end bears against the upper annular surface of the spacer ring 31'5 which rests on the upper enlarged annular portion 30 1 of the valve member 73e. The spring biased valve 300 is preferably employed where the effect of temperature changes on the setting of the valve must be minimized, it being apparent that the changes in temperature will effect the setting of compressed gas biased valves more greatly than the spring biased valves. To make the valve 300 even more insensitive to temperature changes, the chamber 320 formed by the bellows sections, the valve member, the mandrel, the sleeve 30e and the closure ring 35e is preferably lled with incompressible liquid.

The filling of the chamber 320 with the incompressible liquid may be accomplished by removing the plug 46e and filling the chamber 320 with the incompressible liquid through the ller port 44e while the valve member is in its Ilower closed position. The ports 57e may then be closed by any suitable closure means after which fluid under pressure is introduced into the bore of the mandrel 25e which, acting through the ports 56e of the mandrel 25e, lthen =moves the valve member upwardly to its open position against the resistance of the biasing spring 312. The excess liquid escapes through the ller port past the plug 46e. The pressure in the mandrel is increased until the valve member is moved to its proper open position. The plug 46e is then screwed in to engage the gasket 47e and close the filler port while the valve member is held in its upper closed position by the uid pressure. The fluid pressure within the mandrel 25e is then released and the force of the biasing spring then -moves the valve member to the lower closed position illustrated in FIGURE 9. This movement of the valve member, and therefore of the bel-lows, creates a vacuum in the chamber 320 so that no or very little gas is present in the spring chamber 320 and therefore the gas lift valve 300 will open and close at the same pressure regardless of the temperature variations under which it operates.

The incompressible fluid in chamber 320 prevents the bellows from being crushed by excessive pressure in the bore of mandrel 25e when the valve member is in fully open position.

It will be apparent that the valves 250 and 300 may by suitable arrangement of the relationship of the ports of the mandrel and the sleeve and the check valve be modified to control ow of uids through the flow passage either into the mandrel from the exterior of the valve or from the interior of the mandrel to the exterior of the valve and that the valve member of each gas lift valve may be made responsive either to lthe pressure within the tubing or to the pressure within the annulus in the same manner as in the embodiments of the gas lift valve of the invention illustrated in FIGURES 4, 6 and 7, respectively.

It will also be apparent that while the valves have been illustrated as having three circumferentially spaced ports 61 in the port ring 59 that the number of the ports, and therefore of the cooperating valve tips on the valve member, may be varied as desired to obtain different rates of flow of the lifting gas through the gas lift valve and that the orifices of the port-s -may also be varied to obtain different rates of flow of the lifting gas.

It will further be apparent that the various forms of the gas lift embodying the invention have means providing a flow passage, s-uch as the flow passage 55 of the valve of FIGURE l, through which lifting gas may flow between the interior of the mandrel and the exterior of the gas lift valve and that such ow of lifting gas through the How passage is controlled by the valve member who-se valve tips 70 are adapted to close the ports 61 of the port rin-g 59 disposed in such flow passage, the provision of the port ring having ports 61 of relatively small diameter in effect restricting the effective orifice of the flow passage.

It will further be seen that the valve member is annular in form and concentric with the mandrel and is provided with a bellows formed of two concentric sections, disposed inwardly and outwardly, respectively, of the annular valve member, which are exposed to the pressure of the interior or bore of the mandrel or of the exterior of the gas :lift valve and that s-uch pressure acting on the bellows tends to move the Ivalve member to its open position to permit ow of fluid between the interior and the exterior of the mandrel through the flow passage.

It will further be seen that the movement of the valve member and of the bellows towards open position is limited by an incompressible liquid which is trapped within .the bellows when the valve member moves to its fully 'open position and which llimits further distortion or deformation of the bellows so that the bellows are protected against excessive pressures from the interior of the mandrel or from the exterior of the valve, as the case may be.

It will further be seen that the valve member is biased towards closed position either by a charge of compressed gas, as in the embodiments of the gas lift valve illustrated in FIGURES 1 through 7, acting on the bellows thereof or by a spring as in the embodiment of the gas lift valve illustrated in FIGURE 9, such biasing means being disposed `in a pressure or housing chamber lof the valve.

It will now be apparent that a new and improved gas lift valve has been illustrated and described whose operative elements are annular in form and concentric with the mandrel about which they are disposed, the mandrel being connectible in the string of tubing to form a section thereof, so that the internal diameter of the mandrel may be as large as that of the tubing in order that the valve not impede the flow of fluids therethrough or the passage of well tools therethrough and so that the outside diameter of the gas lift valve may be relatively small in order not to impede the passage of well tools or the flow of fluid-s through the annulus between the tubing and the well casmg.

It will further be seen that the operative elements of the gas lift valve are disposed between the mandrel and the sleeve mounted thereabout and are thus not exposed either to the bore of the mandrel or to the annulus between the tubing and the well casing.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A gas lift valve comprising: a tubular body adapted for connection in :a tubing; a sleeve disposed about said body to define a ow passage between said body and said sleeve, said body and said sleeve having ports therein communicating with said flow passage and with the interior of said body 'and the exterior of the sleeve respectively; annular port seat means disposed in said ow passage between the ports of said body and the ports of said sleeve and having a plurality of circumferentially spaced flow ports therein; an annular valve carrier member disposed between said body and said sleeve and having a plurality of circumferentially spaced longitudinally extending valve members thereon each engageable with one of said flow ports to prevent fluid through said passage between said ports of said body and said ports of said sleeve; and a pair of coaxially aligned annular bellows disposed in said flow passage, one end of each of said bellows being sealingly connected to one end of said flow passage, the other end of each of said bellows being sealingly connected to said annular valve carrier member, sai-d annular valve carrier member and said bellows enclosing within the bellows a liuid pressure charge which expands the bellows and urges said annular valve carrier member toward said annular port seat means whereby said valve members on said valve carrier member are biased into engagement with said flow ports; s-aid spaced depending valve members permitting free passage of fluid between the outer sides of the pair of bellows whereby the Huid pressure within the passage between the bellows and the annular port seat means acts on said bellows to cause movement of said valve members to open position when said fluid pressure exceeds the pressure of the charge confined within the bellows.

2. The gas lift valve of claim 1, and means including van incompressible liquid within said bellows chamber limiting iiexing of said pair of bellows by pressure tending to move said valve member to open position when said valve member is in open position.

3. A gas lift valve including: a tubular mandrel adapted for connection in a tubing string and having a flow passage therethrough; a sleeve disposed about said tubular mandrel and spaced therefrom to define a ow passage therebetween; annular port means disposed in the How passage sealingly cooperating with said mandrel and said sleeve -and having at least a plurality of circumferentially separated flow ports therein providing flow controlling communication between the exterior of said sleeve and the bore of said tubular mandrel through said flow passage; a pair of coaxial annular bellows disposed in said flow passage, one end of each lbellows being sealingly connected to one end of said flow passage; annular means connected to the other end of each bellows sealingly enclosing within the bellows a fluid pressure charge which expands the bellows and urges said annular means toward said port means; a valve cooperating with each of said flow ports and means connecting each valve with the annular means for movement thereby, said connector means being constructed and arranged to allow free passage of fluid between the outer sides of the two bellows; and a pair of ports, one through said mandrel :and the other through said sleeve on opposite sides of said annular port means for communicating the region exterior of the sleeve with the interior of the mandrel through said flow ports.

4. A gas lift valve including: a tubular mandrel adapted for connection in a tubing string and having a flow passage therethrough; a sleeve disposed about said tubular mandrel and spaced therefrom to define a flow passage therebetween; annular port means disposed in the flow passage in sealing cooperation with said mandrel and said sleeve and having at least a plurality of circum- Iferentially separated flow ports therein providing flow controlling communication between the exterior of said sleeve -and the bore of said tubular mandrel through said flow passage; valve means disposed in said flow passage between said mandrel and said sleeve and having a plurality of valve members depending therefrom and each engageable with one of the flow ports of said port means for closing said flow ports of said port means to prevent flow of fluid through said passageway; annular bellows means comprising a pair of axially aligned bellows members disposed in said flow passage and operatively connected at one end to one of said mandrel :and said sleeve and at the opposite end to said valve' means and movably supporting said valve means and the valve members depending therefrom in said passage, said bellows means sealing between said mandrel and said sleeve, said bellows means and said mandrel and sleeve Idefining a chamber sealed off :from iiuid pressure of fluid iiowing through said passage; said spaced valve members permitting passage of fluids therebetween to act on the exterior of each of said bellows members of said bellows means and on said annular valve means, said bellows and said -annular valve means being exposed to pressure from within said passage from one of the bore of said mandrel and the exterior of said sleeve for -actuation by such pressure for moving said valve members of said valve means toward an open position wherein said flow ports of said port means are open when said pressure attains a predetermined value; said fluid pressure chamber between said mandrel and Said sleeve within said bellows holding a pressure fluid :for acting on said annular valve means for biasing said valve members on said valve means into position closing said flow ports of said port means; annular check valve means in said passage controlling flow of uids between said port means .and the bore of said mandrel; and means securing said check valve means in said passage.

5. A gas lift valve of the character set forth in claim l wherein the tubular body has a longitudinal bore of a `diameter not smaller than the internal diameter of the tubing to which the body is connectible to provide an uninterrupted flow passage from the tubing through the body.

6. A gas lift valve including: a tubular mandrel adapted to be connected in a string of well flow tubing to constitute a section thereof; tubular sleeve means mounted on said mandrel and surrounding the same in spaced relation thereto to provide an annular space therebetween and define an annular flow passage Ibetween said mandrel and said sleeve means; said mandrel and said sleeve means having ports therein communicating with said flow passage and with the interior of said mandrel and the exterior of said sleeve means respectively; annular port seat means disposed in said flow passage between the ports of said mandrel and the ports of said sleeve means and having a plurality of circumferenti-ally spaced flow ports therein; an annular valve carrier unember disposed between said mandrel and said sleeve means tand movable longitudinally in the annular space therebetween, said valve carrier member having a plurality of circumferentially spaced longitudinally extending valve members thereon each engageable with one of said ow ports in said annular port seat means to prevent fluid flow through said passage between said ports of said mandrel and said ports of said sleeve means; and a pair of coaxial annular bellows disposed in sai-d annular space and having one end of each of said bellows sealingly connected to one of said mandrel and sleeve means and the other end of each of said bellows being sealingly connected to said annular valve carrier member; said annular valve carrier member, said bellows, said mandrel and said sleeve defining an annular biasing means chamber closed off from fluid communication with the flow passage through said annular space; biasing means confined within said annular biasing means chamber and acting on said annular valve carrier member to urge said annular valve carrier member toward said annular port seat means whereby said valve members on said valve carrier member are biased into engagement with said ow ports of said annular port seat means to close off flow through said flow ports therein; said spaced valve ymembers permitting free passage of fluid between the outer sides of the pair of bellows defining said biasing means chamber whereby the uid pressure [within the passage between the bellows and the annular port se-at means acts on said bellows to cause movement of said valve members to open position when said fluid pressure exceeds the pressure of the biasing means confined within the bellows chamber.

7. A gas lift valve with the character set forth in claim 6 wherein means is provided within said biasing chamber for limiting movement of said annular valve carrier member -away from said annular port seat means.

8. A gas lift valve of the character set forth in claim 6 wherein said biasing means confined within said annular biasing means chamber comprises annular spring means engaging said annular valve carrier member biasing said valve carrier member toward said annular port seat means.

References Cited by the Examiner UNITED STATES PATENTS 2,368,999 2/1945 OLeary 103-232 2,532,448 12/1950 Hasselhorn 137--786 2,748,792 6/1956 Davis 137--155 2,855,952 10/1958 Tausch 103-232 X 3,045,759 7/1962 Garrett 137-155 X 3,062,238 11/1962 Boyd 137-786 WILLIAM F. ODEA, Primary Examiner.

ISADOR WEIL, ALAN COHAN, Examiners. 

1. A GAS LIFT VALVE COMPRISING: A TUBULAR BODY ADAPTED FOR CONNECTION IN A TUBING; A SLEEVE DISPOSED ABOUT SAID BODY TO DEFINE A FLOW PASSAGE BETWEEN SAID BODY AND SAID SLEEVE, SAID BODY AND SAID SLEEVE HAVING PORTS THEREIN COMMUNICATING WITH SAID FLOW PASSAGE AND WITH THE INTERIOR OF SAID BODY AND THE EXTERIOR OF THE SLEEVE RESPECTIVELY; ANNULAR PORT SEAT MEANS DISPOSED IN SAID FLOW PASSAGE BETWEEN THE PORTS OF SAID BODY AND THE PORTS OF SAID SLEEVE AND HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED FLOW PORTS THEREIN; AN ANNULAR VALVE CARRIER MEMBER DISPOSED BETWEEN SAID BODY AND SAID SLEEVE AND HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED LONGITUDINALLY EXTENDING VALVE MEMBERS THEREON EACH ENGAGEABLE WITH ONE OF SAID FLOW PORTS TO PREVENT FLUID THROUGH SAID PASSAGE BETWEEN SAID PORTS OF SAID BODY AND SAID PORTS OF SAID SLEEVE; AND A PAIR OF COAXIALLY ALIGNED ANNUALR BELLOWS DISPOSED IN SAID FLOW PASSAGE, ONE END OF EACH OF SAID BELLOWS BEING SEALINGLY CONNECTED TO ONE END OF SAID FLOW PASSAGE, THE OTHER END OF EACH OF SAID BELLOWS BEING SEALINGLY CONNECTED TO SAID ANNULAR VALVE CARRIER MEMBER, SAID ANNULAR VALVE CARRIER MEMBER AND SAID BELLOWS ENCLOSING WITHIN THE BELLOWS A FLUID PRESSURE CHARGE WHICH EXPANDS THE BELLOWS AND URGES SAID ANNULAR VALVE CARRIER MEMBER TOWARD SAID ANNULAR PORT SEAT MEANS WHEREBY SAID VALVE MEMBERS ON SAID VALVE CARRIER MEMBER ARE BIASED INTO ENGAGEMENT WITH SAID FLOW PORTS; SAID SPACED DEPENDING VALVE MEMBERS PERMITTING FREE PASSAGE OF FLUID BETWEEN THE OUTER SIDES OF PAIR OF BELLOWS WHEREBY THE FLUID PRESSURE WITHIN THE PASSAGE BETWEEN THE BELLOWS AND THE ANNULAR PORT SEAT MEANS ACTS ON SAID BELLOWS TO CAUSE MOVEMENT OF SAID VALVE MEMBERS TO OPEN POSITION WHEN SAID FLUID PRESSURE EXCEEDS THE PRESSURE OF THE CHARGE CONFINED WITHIN THE BELLOWS. 